The idea is to deliver enough energy to kill most of the (living) bacteria cells, without actually cooking the (dead) meat tissue. The problem is that there is no way to tell (just from the word) exactly what kind of “radiation” they are using. X-rays or gamma rays are most likely; particle accelerators would be far too expensive.
In any case, the potential danger has nothing to do with the beef. Even if the beam does zap some of that DNA, those cells are dead, and aren’t about to infect anything. I would be more worried about potential mutations in the bacteria, if the dosage is not strong enough to kill it all.

@ Bill – I can’t tell if that question is sarcastic, rhetorical, or serious. Assuming the latter: Microwaves have a much longer wavelength than sterilizing radiation. They won’t do much to kill the bacteria directly, but they will heat up the water molecules in the food, and if it all gets hot enough to denature the proteins, that will effectively sterilize the food. It’s also quite likely to render it inedible, but that’s beside the point.

@ Bill – This leads right back to the linguistic inadequacy of the word “radiation”. Despite the fact that the word “nuke” is often used in the sense of “cook food in a microwave oven”, there is nothing “nuclear” about microwaves.

I assume Bill forgot to include another <sarcasm> token, but stll: you can put just about anything in the beam from a high power particle accelerator, and it still won’t produce a (nuclear) explosion, unless the material consists of unstable isotopes (and is large enough to form a critical mass). On the other hand, putting a potato (or an egg) in an ordinary microwave over will produce a fairly messy (domestic) explosion.
P.S. Thanks to MiB for the Gumby link. I was surprised to see how old (1956) the idea of nuking food products is.

One took a dime from their (or their dad’s) pocket and they put it in some machine and when it came out they put it in a blue plastic holder with the nuclear symbol on it. I don’t remember exactly what was done to it – so I just looked it up. They were irradiated – https://www.orau.org/ptp/collection/medalsmementoes/dimes.htm

Most kids (myself included) eventually pulled out the dimes and spent them – although I think Robert still had his when he lived at home before we married and it is probably here – somewhere.

So, they took your dime, which was 90% silver in 1964, irradiated it so the silver now had a half-life of 25 seconds, they put it in a Geiger counter, to prove it’s radioactive, then give it to you, at which point the silver has already begun to decay into cadmium, so you now have a worthless, fiat dime! And the very next year they stopped making silver dimes and quarters! It’s all a conspiracy to take silver away from the people!

@ larK – One of the articles that my search for “irradiated dimes” turned up implied that the trick only worked with silver dimes, and was discontinued after clad coinage came out in the mid-60’s. However, there was another comment that claimed that the Geiger counter used to “prove” the radioactivity in the treated dime wasn’t selective enough, and might have been reporting normal background radiation as well. Nevertheless, as you mentioned, with the short half-life it is pretty clear that none of those dimes would be detectable now by the radioactivity.

And they’re still mostly silver as only an infinitesimal quantity of regular silver was converted into radioactive silver; otherwise, it wouldn’t have been very healthy for the plastic casing, the visitors or the demonstrators.